Procedures for the Evaluation of Hazards

Although progress has been made in methods of evaluating hazards for self-reactive substances, further improvement is required on the international level. To insure safety, one needs to take the measures which are consider the best for each specific occasion. The flow chart shown in Fig.1.1 has been suggested by people involved with safety to evaluate whether new substances are hazardous reactive chemicals. 

If one needs to handle substances whose properties are unknown, a survey of the literature should be done first to determine whether the substances in question are known to be hazardous. If the literature provides enough information and data, no further evaluation is necessary. The substances should be treated in accordance with the instructions described in the references. 

However, if reference materials indicate that the new substances may be hazardous, and if the level of their hazards is not known, then a prediction based on calculations is recommended. The advantage of a calculation is that it gives some indication of the level of hazard without requiring any experiments. 

A calculation does not require any facilities like those needed for experiments, and people can easily become familiar with the calculations that enable predictions. In principle, this means that calculation can be applied more widely. However, some calculations are impossible, and occasionally the results of the calculations are not reliable. In such cases, conclusions cannot be reached on the basis of calculations alone screening tests become necessary. Most companies and institutes which develop reactive chemicals now have appropriate facilities to run screening tests. 

If a substance becomes commercialized and available in a large quantity, screening tests are not enough. Large-scale standard tests are necessary to define the safety of the substance, and if the existence of hazards is indicated by these standard tests, measures to make the safe handling of the substance possible must be sought 

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